Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Castle Game Engine - An open-source 3D/2D game engine for ObjectPascal.
Mailbird - Mailbird is the best email client for Windows 7, 8 and 10
Open 3D Engine - Open 3D Engine is an open-source 3D game development engine in real-time.
eM Client - eM Client is a fully-featured email client for Windows and macOS with a clean and easy-to-use interface. eM Client also offers features for calendars, tasks, contacts, notes, and chat.
Godot Engine - Feature-packed 2D and 3D open source game engine.